Aspirin is as effective as low molecular weight heparins in preventing symptomatic venous thromboembolism following arthroscopic anterior cruciate ligament reconstruction.

OBJECTIVE: The optimal agent for thromboprophylaxis following arthroscopic anterior cruciate ligament reconstruction (ACLR) remains unclear, particularly in patients with a low baseline risk for venous thromboembolism (VTE). This retrospective cohort study aims to compare the effectiveness and safety of aspirin versus low molecular weight heparins (LMWHs) in this specific patient population. METHODS: We analyzed data from patients who underwent ACLR between March 2016 and March 2021, focusing on those with a low risk for VTE. High-risk individuals, identified by factors such as cardiac disease, pulmonary disease, diabetes mellitus, previous VTE, inflammatory bowel disease, active cancer, and a BMI > 40, were excluded (n = 33). Our approach included a thorough review of medical charts, surgical reports, and pre-operative assessments, complemented by telephone follow-up conducted over a 3-month period by a single investigator. We assessed the incidence of symptomatic VTE, including deep vein thrombosis and pulmonary thromboembolism, as the primary outcome. The secondary outcomes included to complications related to the surgery and thromboprophylaxis. Statistical analysis included descriptive statistics, univariate logistic regression models, and calculations of incidence rates. RESULT: In our study, 761 patients (761 knees) were included, with 458 (60.18%) receiving aspirin and 303 (39.82%) receiving LMWH. The two groups showed no significant differences in demographic factors except for age. The incidence of VTE was reported at 1.31% (10 individuals). Specifically, five patients in the aspirin group (1.09%) and five patients in the LMWH group (1.65%) developed a symptomatic VTE event (p = 0.53). Additionally, the two groups did not significantly differ in terms of other complications, such as hemarthrosis or surgical site infection (p > 0.05). Logistic regression analysis revealed no statistically significant difference in VTE risk between the two groups. CONCLUSION: This study, focusing on isolated ACLR in patients with a low baseline risk for venous thromboembolism, demonstrated that aspirin is equally effective as low molecular weight heparins for VTE prophylaxis following this surgery. LEVEL OF EVIDENCE: III.

Kinematic Alignment Technique Outperforms Mechanical Alignment in Simultaneous Bilateral Total Knee Arthroplasty: A Randomized Controlled Trial.

BACKGROUND: The aim of this study was to compare the clinical results of kinematic alignment (KA) with those of mechanical alignment (MA) in single-stage bilateral total knee arthroplasty. METHODS: In this double-blinded randomized controlled trial, 65 patients who had bilateral knee osteoarthritis underwent simultaneous bilateral total knee arthroplasty. One knee was randomly selected to be operated on with the calipered-KA technique and the other with MA. The participants were assessed via the Oxford Knee Score, Western Ontario and McMaster Universities Osteoarthritis Index questionnaire, and visual analog scale before the surgery and the same plus the Forgotten Joint Score at their last follow-up visit, 2 years postoperatively. Maximum knee flexion and the time reaching maximum knee flexion, named the recovery time, were also recorded. Hip-knee-ankle angle, medial proximal tibial angle, and lateral distal femoral angle were measured before and after the surgery using 3-joint-view radiographs. RESULTS: At 2 years, there were significant differences between the KA and MA techniques in terms of duration of surgery, recovery time, and final Western Ontario and McMaster Universities Osteoarthritis Index, Forgotten Joint Score, and maximum flexion range in favor of KA (P < .05), but no significant difference in visual analog scale score or Oxford Knee Score. In patients who have a preferred knee, the KA knee was preferred over the MA knee by most patients. No prosthetic failure or revision was reported in either group. CONCLUSIONS: The KA technique yields acceptable functional outcomes compared to the MA technique. The KA technique was associated with a shorter surgery time, a faster recovery time, and higher patient satisfaction in 2-year follow-ups. Larger multicenter studies with longer follow-ups are warranted to confirm these findings. LEVEL OF EVIDENCE: I.

Subtrochanteric Shortening Osteotomy Provides Superior Function to Trochanter Slide Osteotomy in THA for Patients With Unilateral Crowe Type IV Dysplasia at a Minimum of 3 Years.

BACKGROUND: Performing THA in patients with high-riding developmental dysplasia of the hip (DDH) is associated with serious complications and technical challenges. Various methods of shortening osteotomy are available to facilitate femoral head reduction during THA in patients with high-riding hips; subtrochanteric shortening osteotomy and trochanteric slide osteotomy plus proximal shortening are the most common techniques. However, which approach is superior remains a topic of controversy. QUESTIONS/PURPOSES: (1) Is there any difference in clinical outcomes (defined as the Harris Hip Score [HHS] and residual limb length discrepancy) at a minimum of 3 years between subtrochanteric shortening osteotomy and trochanteric slide osteotomy in patients with Crowe Type IV DDH who underwent THA? (2) Is there any difference in the risk or type of complications between the two approaches? METHODS: We performed a retrospective, comparative study of two groups (subtrochanteric shortening osteotomy versus trochanteric slide osteotomy) matched for sex and preoperative HHS at a minimum of 3 years of follow-up. Between 2010 and 2018, we performed 67 THAs in patients with unilateral Crowe Type IV DDH. During that time, we generally used a trochanteric slide osteotomy for THA in all patients with Crowe Type IV hips and performed subtrochanteric shortening osteotomy when a conical stem was not available. A total of 42% (28) had THA with subtrochanteric shortening osteotomy, and 58% (39) had THA with trochanteric slide osteotomy. Of those, 89% (25) and 74% (29), respectively, were accounted for with complete datasets for possible matching at a minimum of 3 years of follow-up. Patients were matched for gender and preoperative HSS (within 10 points), leaving 22 patients in each group (79% of the subtrochanteric shortening osteotomy group and 56% of the trochanteric slide osteotomy group) for evaluation and analysis. Age (42 versus 46 years), gender (female: 73% versus 73%), preoperative HSS (40 versus 40), and preoperative leg length discrepancy (5.9 versus 5.3 cm) were comparable between the two groups (p > 0.05). The trochanteric slide osteotomy group exclusively received Cone Wagner (Zimmer) implants (100%), while Corail (DePuy Synthes) implants (77%) were the most commonly used in the subtrochanteric shortening osteotomy group. HHS at a minimum of 3 years as well as the presence or absence of a limp and Trendelenburg sign, functional leg length discrepancy, nonunion, nerve palsy, and other surgical complications were recorded and compared between the groups based on data drawn from a longitudinally maintained institutional database. RESULTS: At a mean follow-up of 73 months, improvement in HHS was greater in the subtrochanteric shortening osteotomy group than in the trochanteric slide osteotomy group (48 ± 4 points versus 36 ± 11 points, mean difference 12 points [95% CI 7 to 17 points]; p < 0.001). Although the preoperative leg length discrepancy was similar between the groups, there was a greater postoperative improvement in the subtrochanteric shortening osteotomy group (44 ± 8 mm and 38 ± 8 mm in the subtrochanteric shortening osteotomy and trochanteric slide osteotomy groups, respectively; p = 0.02). The risk of nonunion was higher with a trochanteric slide osteotomy than with a subtrochanteric shortening osteotomy (23% [5 of 22] versus 0% [0 of 22]; p = 0.048). Other complications, including intraoperative periprosthetic fractures, nerve palsy, heterotopic ossification, revision surgery, and dislocation, did not differ between the groups. CONCLUSION: In patients with Crowe Type IV hips undergoing THA, surgeons might consider subtrochanteric shortening osteotomy rather than trochanteric slide osteotomy to minimize the risk of nonunion and achieve superior hip function. Better correction of leg length discrepancy may also be possible with subtrochanteric shortening osteotomy. The long-term survivorship of hips after these two techniques, as well as the influence of the specific anatomy of the proximal femur on the choice of technique, remain to be explored in future studies. LEVEL OF EVIDENCE: Level III, therapeutic study.

Assessing Leg Length Discrepancy Is Necessary Before Arthroplasty in Patients With Unilateral Crowe Type IV Hip Dislocation.

BACKGROUND: THA for high-riding developmental dysplasia of the hip (DDH) is challenging in terms of length equalization. Although previous studies suggested preoperative templating on AP pelvic radiographs is insufficient in patients with unilateral high-riding DDH because of hypoplasia of the hemipelvis on the affected side and unequal femoral and tibial length on scanograms, the results were controversial. The EOS™ (EOS™ Imaging) is a biplane X-ray imaging system using slot-scanning technology. Length and alignment measurements have been shown to be accurate. We used the EOS to compare the lower limb length and alignment in patients with unilateral high-riding DDH. QUESTIONS/PURPOSES: (1) Is there an overall leg length difference in patients with unilateral Crowe Type IV hip dysplasia? (2) In patients with unilateral Crowe Type IV hip dysplasia with an overall leg length difference, is there a consistent pattern of abnormalities in the femur or tibia that account for observed differences? (3) What is the impact of unilateral high-riding Crowe Type IV dysplasia on femoral neck offset and knee coronal alignment? METHODS: Between March 2018 and April 2021, we treated 61 patients with THA for Crowe Type IV DDH (high-riding dislocation). EOS imaging was performed preoperatively in all patients. Eighteen percent (11 of 61) of the patients were excluded because of involvement of the opposite hip, 3% (two of 61) were excluded for neuromuscular involvement, and 13% (eight of 61) had previous surgery or fracture, leaving 40 patients for analysis in this prospective, cross-sectional study. Each patient's demographic, clinical, and radiographic information was collected with a checklist using charts, Picture Archiving and Communication System, and an EOS database. EOS-related measurements that were related to the proximal femur, limb length, and knee-related angles were recorded for both sides by two examiners. The findings of the two sides were statistically compared. RESULTS: The overall limb length was not different between the dislocated and nondislocated sides (mean 725 ± 40 mm versus 722 ± 45 mm, mean difference 3 mm [95% CI -3 to 9 mm); p = 0.08). Apparent leg length was shorter on the dislocated side (mean 742 ± 44 mm versus 767 ± 52 mm, mean difference -25 mm [95% CI -32 to 3 mm]; p < 0.001). We observed that a longer tibia on the dislocated side was the only consistent pattern (mean 338 ± 19 mm versus 335 ± 20 mm, mean difference 4 [95% CI 2 to 6 mm]; p = 0.002), but there was no difference between the femur length (mean 346 ± 21 mm versus 343 ± 19 mm, mean difference 3 mm [95% CI -1 to 7]; p = 0.10). The femur of the dislocated side was longer by greater than 5 mm in 40% (16 of 40) of patients and shorter in 20% (eight of 40). The mean femoral neck offset of the involved side was shorter than that of the normal side (mean 28 ± 8 mm versus 39 ± 8 mm, mean difference -11 mm [95% CI -14 to -8 mm]; p < 0.001). There was a higher valgus alignment of the knee on the dislocated side with a decreased lateral distal femoral angle (mean 84° ± 3° versus 89° ± 3°, mean difference - 5° [95% CI -6° to -4°]; p < 0.001) and increased medial proximal tibia angle (mean 89° ± 3° versus 87° ± 3°, mean difference 1° [95% CI 0° to 2°]; p = 0.04). CONCLUSION: A consistent pattern of anatomic alteration on the contralateral side does not exist in Crowe Type IV hips except for the length of the tibia. All parameters of the limb length could be shorter, equal to, or longer on the dislocated side. Given this unpredictability, AP pelvis radiographs are not sufficient for preoperative planning, and individualized preoperative planning using full-length images of the lower limbs should be performed before arthroplasty in Crowe Type IV hips. LEVEL OF EVIDENCE: Level I, prognostic study.

Impaction Grafting Is Sufficient to Address Acetabular Deficiency During Total Hip Arthroplasty of Most Dysplastic Hips With Over 30% Bone Defect.

BACKGROUND: Addressing acetabular deficiency during arthroplasty of dysplastic hips is challenging. We assessed outcomes of a protocol for choosing either impaction or structural graft for this purpose. METHODS: This retrospective study included 59 patients (71 hips) with a dysplastic hip and over 30% uncoverage that underwent cementless total hip arthroplasty. Morselized impaction grafting was performed for hips where initial stability of the acetabular cup was achieved. In others, a shelf graft was inserted before implantation of the acetabular cup. Outcomes were assessed at a minimum follow-up of 4 years. RESULTS: Fifty-seven (80.3%) hips underwent impaction grafting and 14 (19.7%) received a structural graft. Mean age at surgery was 48.1 ± 13.5 (18-68) years for impaction and 48.6 ± 14 (24-70) years for shelf grafts. Mean increase in Harris Hip Score was 51.5 ± 9.3 and 50 ± 11.2 for the impaction and structural groups, respectively, at a mean follow-up of 92 (49-136) months (P = .6). Heterotopic ossification occurred in 16 patients in the impaction group vs none in the structural group (P = .004). Radiologically, mean percentages of cup coverage provided by the graft were 47.8 ± 10.9% and 48.9 ± 13.3% in the impaction and structural groups, respectively (P = .75). All but one of shelf grafts united to host bone and all impaction grafts incorporated. There was one case of cup loosening in the structural graft group. CONCLUSION: Most dysplastic acetabula with over 30% defect can be addressed using a cementless cup and impaction grafting, with good results in the midterm. In about 20% of cases, initial press-fit is not attainable and structural support-like shelf graft becomes necessary. LEVEL OF EVIDENCE: IV.

Rotating hinge knee causes lower bone-implant interface stress compared to constrained condylar knee replacement.

PURPOSE: To compare the stresses at bone-arthroplasty interface of constrained and semi-constrained knee prostheses, using the finite element (FE) method as a predictor of the survivorship of the implants. METHODS: Three-dimensional FE models of the knee implanted with rotating hinge (RHK) and legacy constrained condylar (LCCK) prostheses were generated to study the loads and stresses for two situations: medial- and lateral collateral ligament deficiencies in full extension. RESULTS: On average, the shear stress developed at bone-implant interface dropped from 16.9 to 13.7 MPa (18.9%), and the interface von Mises stress lowered from 37.6 to 30.2 MPa (19.6%) in RHK compared to those in LCCK prostheses. RHK design also resulted in a more uniform stress distribution at the interfaces in both femur and tibia. The average polyethylene liner stress dropped from 9.6 to 2.6 MPa (a 72.7% decrease) in RHK design when compared to that in LCCK design. CONCLUSION: The more uniform interface stress suggests fewer density changes at the periprosthetic regions due to bone remodelling. Moreover, the lower polyethylene stresses are likely to reduce wear and damage. These findings reveal that the RHK design may have more favorable mechanical features compared to LCCK design in full extension boundary conditions, implying a potentially better survivorship. However, the findings should be interpreted cautiously as other configurations were not investigated.

Hemi-pelvic slope is correlated with the acetabular depth in adults-a radiological study.

OBJECTIVE: The purpose of this study was to determine if there is an anatomic relationship between pelvic geometry and acetabular depth. MATERIALS AND METHODS: One hundred and fifty-one anteroposterior pelvic radiographs (157 hip joints) were selected and analyzed in a retrospective fashion. Six parameters, including iliac offset, ischial offset, acetabular offset, pelvic height, center-edge (CE) angle of Wiberg, and acetabular index (AI) angle of Tönnis were measured for each of the hip joints. Based on the defined variables, three formulas (formulas 1, 2, and 3) were calculated to represent the hemi-pelvis slope. RESULTS: There was a strong relationship between the hemi-pelvis slope and probability of acetabular dysplasia. Wider upper pelvis was associated with deeper acetabulum and wider lower pelvis was associated with dysplastic acetabulum. CONCLUSIONS: Pelvic anatomic dimensions and the relationship between them are strongly correlated with hip dysplasia indices. Dysplastic hips tend to be found in pelvises with lower slope (low width of the upper pelvis at the level of iliac crest and high width of the lower part at the level of ischium).

Patient's Height and Hip Medial Offset Are the Main Determinants of the Valgus Cut Angle During Total Knee Arthroplasty.

BACKGROUND: Valgus cut angle (VCA), defined as the angle between the anatomical and the mechanical axes of femur, is an important parameter upon which a critical step of knee arthroplasty is based. Some variables have been proposed to affect the magnitude of this cut. However, little information is available regarding whether a generic value can be used, or if a patient-specific value from a long leg X-ray, or factors that can be determined preoperatively, is necessary to accurately set the VCA. METHODS: Standard standing 3-joint views were used to measure a number of anatomical measurements in 358 limbs, 202 patients (116 women, 86 men). Neck-shaft angle, medial offset, femoral length (FL), distal femoral articular angle, and VCA were measured. Demographic data including gender and height were extracted from hospital charts. The correlation of VCA with each of the other factors was evaluated using linear regression and t-test and finally multivariate analysis. RESULTS: The average VCA was 5.76° (range 4-8). Gender and distal femoral articular angle were not related to VCA (P = .343 and .995). FL was found to be a function of height with similar effects on multivariate analysis. Only the height (or FL) and femoral offset were identified as independent factors, with a negative correlation for the former (P < .001) and a positive correlation for the latter (P < .001). CONCLUSION: Femoral offset and height are the 2 independent factors determining VCA. Other parameters are indirectly related to these 2 factors. Tall patients with a small femoral offset have smaller VCA and short patients with a large offset have larger VCA. The wide variety of VCA values does not support using a generic value for all patients during knee arthroplasty.

The results of two-stage revision TKA using Ceftazidime-Vancomycin-impregnated cement articulating spacers in Tsukayama Type II periprosthetic joint infections.

PURPOSE: This study examined the success and factors associated with failure, of using cement spacers impregnated with high-dose Ceftazidime and Vancomycin when performing two-stage revision for infected total knee arthroplasty (TKA). METHODS: A retrospective analysis was performed using a prospectively collected database of 82 patients (median age 68 years, range 39-87) with a confirmed deep TKA infection treated with a two-stage revision. All cement spacers were impregnated with high-dose Ceftazidime and Vancomycin. The rate of success was recorded-an association between failure of treatment, and patient factors, previous surgical treatment, and microbial characteristics was sought. RESULTS: The mean time to infection from index arthroplasty was 45 months (range 3-240). The initial two-stage revision was successful in 70/82 patients (85.4 %), who remained free of infection at average follow-up of 36.2 months (range 24-85). A second two-stage revision for infection was required in 12/82 patients (14.6 %), which was successful in 4/12 (33 %). A third two-stage revision was performed in three patients, all of whom had a polymicrobial infection of which only one patient had successful eradication of infection. Recurrent infection was correlated with irrigation and debridement with implant retention prior to initial two-stage revision (p < 0.01), polymicrobial infections (p = 0.035), and infections presenting <6 months after index surgery (p = 0.031). No correlation was seen with age, BMI, type of organism, diabetes mellitus, or Charlson Comorbidity Index. CONCLUSION: The findings of this study suggest that the combination of Ceftazidime and Vancomycin in cement spacers is as efficacious as other published single or combined antibiotic mixtures, which is clinically relevant to clinicians treating this difficult problem in the setting of patients with compromised renal function.

The Use of a Closed-Suction Drain in Revision Knee Arthroplasty May Not Be Necessary: A Prospective Randomized Study.

BACKGROUND: The benefit of suction drains (SD) for the first 24-48 hours following joint replacement surgery is controversial. We aimed to determine if there is any difference in the early outcome of revision TKA when performed with, or without SD. METHODS: 83 cases indicated for revision knee arthroplasty were randomized to receive (42) or not receive (41) a deep intra-articlular drain. First-stage revisions for treating periprosthetic infection were excluded. Patients were statistically compared for demographic parameters, early complications and early knee functional outcome. The assessed outcomes included total blood loss, number of transfusions, fever and wound complication rate at 24 months follow-up. In addition, the change in knee society score at 12 weeks postoperatively was compared between the groups. RESULTS: There were no significant difference in demographic factors, wound complications, knee scores at 12 weeks and infection rate 24 months after surgery in either group. Average blood loss was 1856ml and 1533ml for the drain and no drain groups, respectively (P value=0.0470). The need for transfusion was significantly less in the no-drain group with an average of 0.15 unit/patient as compared to an average 0.37 unit/patient for the drain group (P value=0.0432). CONCLUSION: We were unable to find a point of superiority for using a drain for revision knee arthroplasty. Future studies with longer follow-up and larger population of patients are needed to make a valid conclusion.

Effect of patellar thickness on knee flexion in total knee arthroplasty: a biomechanical and experimental study.

A biomechanical computer-based model was developed to simulate the influence of patellar thickness on passive knee flexion after arthroplasty. Using the computer model of a single-radius, PCL-sacrificing knee prosthesis, a range of patella-implant composite thicknesses was simulated. The biomechanical model was then replicated using two cadaveric knees. A patellar-thickness range of 15 mm was applied to each of the knees. Knee flexion was found to decrease exponentially with increased patellar thickness in both the biomechanical and experimental studies. Importantly, this flexion loss followed an exponential pattern with higher patellar thicknesses in both studies. In order to avoid adverse biomechanical and functional consequences, it is recommended to restore patellar thickness to that of the native knee during total knee arthroplasty.

Is arthroplasty immediately after an infected case a risk factor for infection?

BACKGROUND: It is common practice in many centers to avoid performing a clean case in a room in which an infected procedure has just taken place. No studies of which we are aware speak to the necessity of this precaution. QUESTIONS/PURPOSES: The purposes of this study were to identify (1) the risk of infection in a group of patients who underwent arthroplasties performed immediately after a first-stage arthroplasty for joint infection; and (2) the risk of superficial and deep infections in these patients compared with a matched group of patients who underwent arthroplasties not performed after an infected surgery. METHODS: Eighty-three patients (85 arthroplasties) who underwent arthroplasties (primary or revision) immediately after patients with known infections underwent surgery in the same operating room (OR) were analyzed for 12 months after surgery to determine the incidence of infection. They were matched for demographic factors and surgery type with a control group of 321 patients (354 arthroplasties) who underwent surgery in an OR that had not just been used for surgery involving patients with infections. We compared the risk of superficial and deep infections between the groups. RESULTS: Patients in the study group were not more likely to have infections develop than those in the control group. One patient in the study group (1.17%) and three in the control group (0.84%) had deep infections develop; the infection in the patient in the study group was caused by a different organism than that of the patient with an infection whose surgery preceded in the OR. Two superficial infections (2.35%) were detected in the study group and 17 (4.8%) were detected in the control group. CONCLUSIONS: With the numbers available, we found that a deep infection was not more likely to occur in a patient without an infection after an arthroplasty that followed surgery on a patient with an infection than in one who had surgery after a clean case. Although sample size was a potential issue in this study, the results may serve as hypothesis generating for future studies. LEVEL OF EVIDENCE: Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

A long-term survivorship comparison between cemented and uncemented cups with shelf grafts in revision total hip arthroplasty after dysplasia.

Long-term outcomes of cemented and uncemented cups were compared in patients with hip dysplasia who had undergone revision hip arthroplasty. Patients had uncontained superolateral acetabular defects reconstructed with a structural allograft. This retrospective study compared 18 cemented acetabular cups to 27 uncemented acetabular cups. Average follow-up was 216 months (range, 96-312). Nineteen acetabular cups (42%) failed due to loosening and were revised. The 10- and 20-year cup survival was 88% and 76% in the uncemented group and 67% and 36% in the cemented group. Log rank analysis showed this difference to be significant (P = .0077). Uncemented acetabular cups performed significantly better than cemented cups.

Nineteen year results of THA using modular 9 mm S-ROM femoral component in patients with small femoral canals.

A retrospective analysis was undertaken of 30 consecutive THA performed in 25 patients with hypoplastic proximal femurs, who had received a 9-mm uncemented modular S-ROM stem. The mean patient age was 42 years (17-69 years), mean height was 152.5 cm (130-170.5 cm), mean weight was 63 kg (39-90 kg), and mean follow-up period was 19 years (range, 12-23 years). Subsidence was seen in 2 hips, with asymptomatic femoral osteolysis present in 11 hips; overall survival of the femoral stem was 93.3%, with two revisions of the femoral component required for aseptic loosening. After a mean follow-up of 19 years, the use of the S-ROM 9 mm femoral stem in the patient with the small femur was associated with a low revision rate due to aseptic loosening of the stem.

Displacement of the hip center of rotation after arthroplasty of Crowe III and IV dysplasia: a radiological and biomechanical study.

To study the direction and biomechanical consequences of hip center of rotation (HCOR) migration in Crowe type III and VI hips after total hip arthroplasty, post-operative radiographs and CT scans of several unilaterally affected hips were evaluated. Using a three-dimensional model of the human hip, the HCOR was moved in all directions, and joint reaction force (JRF) and abductor muscle force (AMF) were calculated for single-leg stance configuration. Comparing to the normal side, HCOR had displaced medially and inferiorly by an average of 23.4% and 20.8%, respectively, of the normal femoral head diameter. Significant decreases in JRF (13%) and AMF (46.13%) were observed in a presumptive case with that amount of displacement. Isolated inferior displacement had a small, increasing effect on these forces. In Crowe type III and IV hips, the HCOR migrates inferiorly and medially after THA, resulting in a decrease in JRF, AMF, and abductor muscle contraction force.

A Wearable Tele-Health System towards Monitoring COVID-19 and Chronic Diseases.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic since early 2020. The coronavirus disease 2019 (COVID-19) has already caused more than three million deaths worldwide and affected people's physical and mental health. COVID-19 patients with mild symptoms are generally required to self-isolate and monitor for symptoms at least for 14 days in the case the disease turns towards severe complications. In this work, we overviewed the impact of COVID-19 on the patients' general health with a focus on their cardiovascular, respiratory and mental health, and investigated several existing patient monitoring systems. We addressed the limitations of these systems and proposed a wearable telehealth solution for monitoring a set of physiological parameters that are critical for COVID-19 patients such as body temperature, heart rate, heart rate variability, blood oxygen saturation, respiratory rate, blood pressure, and cough. This physiological information can be further combined to potentially estimate the lung function using artificial intelligence (AI) and sensor fusion techniques. The prototype, which includes the hardware and a smartphone app, showed promising results with performance comparable to or better than similar commercial devices, thus potentially making the proposed system an ideal wearable solution for long-term monitoring of COVID-19 patients and other chronic diseases.

The Effect of Ozone (O3) versus Hyaluronic Acid on Pain and Function in Patients with Knee Osteoarthritis: A Systematic Review and Meta-Analysis.

BACKGROUND: Of the pharmacological modalities for knee osteoarthritis (OA), intra-articular injections including ozone (O3) and hyaluronic acid (HA) are commonly used for reducing pain and improving function. In this systematic review and meta-analysis, we aimed to compare the effect of O3 versus HA in reducing pain and increasing function in patients with knee OA. METHODS: After searching databases, we included 6 randomized controlled trials on patients with knee OA that compared the effects of intra-articular injection of ozone versus HA. The primary outcome was visual analogue scale (VAS) of pain. The secondary outcome was Western Ontario and McMaster Universities Arthritis Index (WOMAC) score. RESULTS: There was a total of 237 patients in the HA group and 230 patients in the Ozone group. Of 6 studies, 4 were in English, 1 was in Persian, and 1 was in German language. The overall Standardized Mean Difference (SMD) for VAS pain did not show a significant difference between the groups although it favored HA injection (1.27 [95%CI: (-0.12)-2.66]). Total WOMAC score showed a significant difference over the time favoring HA injection (4.5 [95%CI: 1.1-8]). However, no single time point showed any significant difference between groups. CONCLUSION: This meta-analysis showed no significant difference between HA and ozone in reducing pain and improving function in patients with knee OA, although the overall results favored HA over ozone. Since previous studies have shown comparable results between HA and placebo, ozone seems to fall in the same category with more placebo effect rather than a real disease-modifier.

Percutaneous Versus Open Hamstring Lengthening in Spastic Diplegic Cerebral Palsy.

BACKGROUND: Open hamstring lengthening (oHSL) is commonly performed to decrease knee contracture and improve gait and posture for children with spastic diplegia. Furthermore, percutaneous hamstring lengthening (pHSL) is also gaining popularity as an alternative to the open approach. This study aimed to compare the results of pHSL versus oHSL and to determine the efficacy and safety of the percutaneous approach. METHODS: This retrospective included 54 patients (108 knees) with spastic diplegia operated for flexed knee gait with either open or percutaneous HSL. The mean age of the participants at the time of surgery was 10.3±1.7 years (age range: 5-25 years) for the open and 8.5±1.5 years (age range: 7-23 years) for the percutaneous group. Overall, 29 and 25 children were subjected to oHSL and pHSL, respectively. RESULTS: The mean durations of follow-up were 19.1 months (range: 12-49 months) and 18.3 months (range: 14-45 months) for oHSL and pHSL groups, respectively. In the open group, the mean of preoperative popliteal angle decreased from 64.3±3.6 to 28.4±4.3 (P<0.001), and in the percutaneous group from 63.8±2.7 to 29.5±2.3 (P<0.001). The obtained results revealed no significant differences between the two approaches leading to a similar improvement among the investigated patients (P=0.83). Although the Gross Motor Function Class Score improved significantly within each group (P<0.001); this improvement was insignificant between the groups (P=0.88). The mean of hospital stay for the percutaneous group was 1.6 days (range:1-3 days) compared to 3.6 days (range: 2-6 days) for the open group, which indicated a significant difference (P=0.001). The mean values of total cost were $333 and $473 in the percutaneous group and open group (P=0.001), respectively. There was no significant difference between the groups regarding the complication rate (P=0.85). CONCLUSION: Percutaneous HSL is a safe, easy, rapid, and brief procedure that is as effective as the open technique for children with spastic diplegia in a short period of time. However, it is essential to examine the effects of this approach during longer follow-ups to generalize the findings of the current study.

Long-Term Results of Treating Large Posttraumatic Tibial Plateau Lesions with Fresh Osteochondral Allograft Transplantation.

BACKGROUND: The use of fresh osteochondral allograft (FOCA) transplantation is a treatment option for large posttraumatic tibial osteochondral defects in young, high-demand patients. We aimed to assess the long-term outcomes of this procedure and factors impacting graft survivorship. METHODS: Evaluated were patients with a posttraumatic tibial plateau defect of >3 cm in diameter and >1 cm in depth who were treated with use of a FOCA, with or without a realignment osteotomy, before September 2007. The primary outcome was survivorship according to Kaplan-Meier analysis, with conversion to arthroplasty or another allograft procedure as the end point. The secondary outcome was the functional outcome of knees with a surviving FOCA, as assessed using the modified Hospital for Special Surgery (mHSS) scoring system. Multivariate Cox regression analysis of the role of potential variables was performed for both outcomes. RESULTS: Included were 113 patients (67 female) with a mean age at the time of the index surgery of 43 years (range, 24 to 72 years) and a mean follow-up of 13.8 years (range, 1.7 to 34 years). Forty-eight conversions to arthroplasty or another FOCA procedure had been performed at a mean of 11.6 years (range, 1.7 to 34 years) after the index surgery. The remaining 65 patients had a mean follow-up of 15.5 years (range, 4.3 to 31.7 years). The mean mHSS score among those with a surviving FOCA was 85.5 (range, 56 to 100) at the most recent follow-up, which was significantly higher than the preoperative value of 69 (range, 48 to 85) (p < 0.001). Graft survivorship was 90% at 5 years, 79% at 10 years, 64% at 15 years, and 47% at 20 years. Complications included infection (1.8%), nonunion (0.9%), and knee pain from hardware (8.8%). Multivariate analysis revealed that older age at the time of surgery, involvement of the medial plateau, and a higher number of previous surgeries were inversely associated with graft survivorship. Having a Workers' Compensation file was associated with less improvement in the mHSS score, and the score tended to decline over time for knees with a surviving FOCA. CONCLUSIONS: FOCA transplantation is a viable option for posttraumatic tibial osteochondral defects, with satisfactory survivorship and functional outcome. Although approximately half of the patients in our study demonstrated graft failure by 20 years, FOCA was an excellent option that delayed the need for arthroplasty. Older patients, those with medial defects, and those with multiple previous surgeries had a less favorable prognosis. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.